Assessing a mountain climber’s condition without noticing their empty backpack

A metaphor: for a mountain climber, which point has the most influence on their condition during the climb?

  • The path ahead?
  • The current situation?
  • The recent past?
  • The starting point?
  • The preparations?

Hard to say? Once the climb has started and until it’s finished, though, are there any points at which the preparations have no influence?

Let’s imagine that factors beyond the climber’s control ruined their preparations, leaving them with no reserves and a limited capability to adapt to environmental changes.

Let’s imagine further that researchers take initial physical and psychological measurements of the climber’s condition at an arbitrary point of the ascent or descent. Due to the design of their measurement system, however, they don’t discover that this climber has an empty backpack.

When the researchers interpret the results, will they understand how the climber’s measurements were influenced by the ruined preparations?  end metaphor

A 2014 Israeli study primary finding was of:

“Fear of terror-induced annual increases in resting heart rate.”

The researchers took 325 measurements each “of 17,380 apparently healthy volunteers” who had “consistent exposure to terror threats.”

The study was opaque in some areas. For example, what was the content and handling of a 4-item anxiety questionnaire?

The supplementary material showed that the headlined “fear of terror” term involved three disparate factors:

  • feeling unsafe;
  • fear of crowds; and
  • anxiety about future harm.

I’d like to understand the bases of why the researchers and the reviewer felt it was appropriate that:

“The scores on these items were averaged to yield a continuous FOT [fear-of-terror] score.”

The researchers probably had sufficient measurements of the subjects’ current conditions. They didn’t have a frame of reference that incorporated the present data with contextual information from each individual’s history back to the earliest parts of their life.

Lacking the links provided by such a framework, the researchers likely misassessed measurements that were influenced by how the subjects’ backpacks were packed. “Fear and C-reactive protein cosynergize annual pulse increases in healthy adults”

Are hippocampal place cells controlled by theta brain waves from grid cells?

This 2015 Canadian rodent study tried to establish that grid cells in the medial entorhinal cortex generated brain waves in the theta frequency range that controlled place cells in the hippocampus part of the limbic system.

The researchers stated:

“Our results deviate from the prediction.”

but a commentary Do the spatial frequencies of grid cells mold the firing fields of place cells? said the researchers:

“Obtained fascinating results, largely supporting the model.”

What’s fascinating to me is the volume of studies on the hippocampus that ignore its position as the seat of emotional memories. Human experiments involving the hippocampus are usually designed to not contain any emotional content.

Two studies showed functions of hippocampal place cells:

A summary study of 118 other studies What do grid cells contribute to place cell firing? provided additional information on grid cells and hippocampal place cells, head direction cells, boundary cells, and cells that encode object locations.

The summary study related to the current study by stating that the research through early 2014 arguably found:

“Grid and place cell firing patterns are not successive stages of a processing hierarchy, but complementary and interacting representations that work in combination.” “Place field expansion after focal MEC inactivations is consistent with loss of Fourier components and path integrator gain reduction”

A common dietary supplement that has rapid and lasting antidepressant effects

This 2012 Italian rodent study found that a common dietary supplement had rapid and lasting antidepressant effects:

“Remarkably, L-acetylcarnitine displayed a clear-cut antidepressant effect already after 3 and 7 d[ays] of daily dosing. No tolerance was developed to the action of L-acetylcarnitine. The drug was even more effective after 21 d[ays], and the effect persisted for at least 2 w[ee]k[s] after drug withdrawal.”

The researchers studied stressed mice and rats to determine that:

  1. An effect of the stress was to epigenetically change the hippocampus part of the limbic system to produce less of an important molecule – type 2 metabotropic glutamate (mGlu2).
  2. A reduction of the mGlu2 molecule decreased the hippocampus’ regulation of the glutamate neurotransmitter.
  3. Under-regulation of glutamate, in turn, caused symptoms of depression.

L-acetylcarnitine reversed the stress-induced underlying causes by acetylating histone proteins that control the transcription of the brain-derived neurotrophic factor (BDNF) and mGlu2 receptors in the hippocampus and prefrontal cortex.

A commentary on this research, Next generation antidepressants, had a Figure 1 that showed possible mechanisms for the effects of L-acetylcarnitine. Epigenetic histone modifications seem to be more easily reversible than epigenetic DNA methylation.

“Currently, depression is diagnosed only by its symptoms,” Nasca says. “But these results put us on track to discover molecular signatures in humans that may have the potential to serve as markers for certain types of depression.”

It’s tempting to extrapolate this study to humans and test whether depression symptoms could be effectively treated with some multiple of a normal L-acetylcarnitine dietary supplement dose of 500 mg at $.25 a day. To cure stress-induced illnesses in humans, though, causes of stress should be removed or otherwise addressed. “L-acetylcarnitine causes rapid antidepressant effects through the epigenetic induction of mGlu2 receptors”

The hypothalamus’ role in how calorie restriction delays aging

This 2015 Portuguese rodent study showed the underlying mechanism to explain why restricting calories delays aging.

A calorie reduction of 20 to 40% increased production of a normally occurring molecule (neuropeptide Y) in the hypothalamus part of the limbic system. The increased amounts of the molecule stimulated autophagy (the breakdown and recycling of cellular components) in hypothalamic neurons.

“Because both hypothalamic autophagy and neuropeptide Y levels decrease with age..modulation of hypothalamic neuropeptide Y levels may be considered a potential strategy to produce protective effects against hypothalamic impairments associated with age and to delay aging.” “Neuropeptide Y stimulates autophagy in hypothalamic neurons”

A study of visual perception that didn’t inform us about human conscious awareness

This 2015 Vanderbilt study with a Princeton reviewer stated that they found “compelling evidence” related to:

“How the brain begets conscious awareness.

Identifying the fingerprints of consciousness in humans would be a significant advancement for basic and medical research, let alone its philosophical implications on the underpinnings of the human experience.”

Let’s begin with the “conscious” part of the study’s conscious awareness goal. A summary article of 105 studies entitled Evolution of consciousness: Phylogeny, ontogeny, and emergence from general anesthesia that I curated found:

The core of human consciousness appears to be associated primarily with phylogenetically ancient structures mediating arousal and activated by primitive emotions.”

The current study ignored the evolutionary bases of human consciousness and didn’t include any limbic system and lower brain areas. The researchers’ biases were further indicated by the statement from their press release:

“Focal theories contend there are specific areas of the brain that are critical for generating consciousness, while global theories argue consciousness arises from large-scale brain changes in activity.”

The researchers were in the global camp of this unnecessary divide.

Let’s next examine the “awareness” part of the study’s conscious awareness goal. The subjects were 24 students in a visual perception experiment that used fMRI. The visual events that were perceived went into the “aware” bucket and the others into the “unaware” bucket.

The study’s subject selection criteria and experiment seemed a little odd for developing “compelling evidence” related to “how the brain begets conscious awareness.” By equating visual perception with awareness, the researchers excluded the contributions of other senses and methods of awareness.

Would it follow from the study’s methodology that blind people can’t be consciously aware?

The supplementary material showed that 7 of the 24 subjects’ results for one experimental condition, and 12 – half – of the subjects’ results for another condition were excluded because they apparently had problems reporting confidence in their visual perception. I wonder why the reviewer agreed that it was appropriate to toss out half of the subjects’ experimental results.

Whatever else it was that the study found, the researchers didn’t reach their goal of developing “compelling evidence” related to “how the brain begets conscious awareness.” “Breakdown of the brain’s functional network modularity with awareness”

Adaptations to stress encourage mutations in a DNA area that causes diseases

This 2015 Baylor study of human cells showed the underlying mechanisms of cellular responses to environmental stressors of cold, heat, hypoxia, and oxidation:

“Because trinucleotide repeats are overrepresented in gene-regulatory proteins, stress-induced trinucleotide repeat mutagenesis may provide a path for the environment to subtly alter gene regulatory networks—with attendant changes in cell behavior—during development, disease, and evolution.”

The study’s overarching framework was that human cells will adapt to best survive in their environment. The study found that the cells’ adaptation responses to stress encouraged the creation of mutations in a DNA area that’s:

“..the cause of multiple human diseases.

This pathway may impact normal cells as they encounter stresses in their environment or during development or abnormal cells as they evolve metastatic potential.”

It’s a logical inference to likewise understand how stressors in a mother’s environment for a developing fetus will cause the fetus to adapt at the cellular level. If, for example, the mother stresses the fetus with inadequate oxygen – hypoxia – this study shows how cells will adapt in a way that favors genetic processes and mutations to survive when they are starved of oxygen.

When the stressed fetus arrives in a different environment after birth, the newborn’s cells are genetically and behaviorally maladapted to certain aspects of a normal environment – to adequate oxygen in this example. The genetic pathways epigenetically adapted to best survive during the fetus’ development in the womb may begin to impact the infant’s development in a normal environment.

Researchers would make significant contributions to the existing science should they further investigate these stress-induced underlying causes. “Environmental stress induces trinucleotide repeat mutagenesis in human cells”

A study on online cooperation with limited findings

This 2015 Cambridge/Oxford study found:

“Global reputational knowledge is crucial to sustaining a high level of cooperation and welfare.”

Basically, the subjects learned how to “game” a cooperative online game, and the researchers drew up their findings.

To me, the study demonstrated part of the findings of the Reciprocity behaviors differ as to whether we seek cerebral vs. limbic system rewards study, the part where the cerebrum was active in:

“Reputation-based reciprocity, in which they help others with good reputations to gain good reputations themselves.”

The current study ignored how people’s limbic system and lower brain areas may have motivated them to cooperate.

I didn’t see how excluding people’s emotional involvement when cooperating with others improved the potential reach of this study’s findings. Doesn’t a person’s willingness to cooperate in person and in online activities usually also include their emotional motivations?

The findings can’t be applied generally to cooperative motivations and behaviors that the researchers intentionally left out of the study. The study’s findings applied just to the artificial environment of their experiment, and didn’t provide evidence for how:

“Cooperative behavior is fundamental for a society to thrive.” “The effects of reputational and social knowledge on cooperation”